edu.ucar.opensky::articles:15415 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T15:05:57.855450 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7sf2x6c A comparison of PMIP2 model simulations and the MARGO proxy reconstruction for tropical sea surface temperatures at last glacial maximum 2009-05-01T00:00:00Z publication https://n2t.org/ark:/85065/d7sf2x6c https://doi.org/10.1007/s00382-008-0509-0 Otto-Bliesner, Bette author Schneider, R. author Brady, Esther C. author Kucera, M. author Abe-Ouchi, A. author Bard, E. author Braconnot, P. author Crucifix, M. author Hewitt, C. author Kageyama, M. author Marti, O. author Paul, A. author Rosell-Melé, A. author Waelbroeck, C. author Weber, S. author Weinelt, M. author Yu, Y. author UCAR/NCAR - Library publisher Results from multiple model simulations are used to understand the tropical sea surface temperature (SST) response to the reduced greenhouse gas concentrations and large continental ice sheets of the last glacial maximum (LGM). We present LGM simulations from the Paleoclimate Modelling Intercomparison Project, Phase 2 (PMIP2) and compare these simulations to proxy data collated and harmonized within the Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface Project (MARGO). Five atmosphere - ocean coupled climate models (AOGCMs) and one coupled model of intermediate complexity have PMIP2 ocean results available for LGM. The models give a range of tropical (defined for this paper as 15°S - 15°N) SST cooling of 1.0 - 2.4°C, comparable to the MARGO estimate of annual cooling of 1.7 ± 1°C. The models simulate greater SST cooling in the tropical Atlantic than tropical Pacific, but interbasin and intrabasin variations of cooling are much smaller than those found in the MARGO reconstruction. The simulated tropical coolings are relatively insensitive to season, a feature also present in the MARGO transferred-based estimates calculated from planktonic foraminiferal assemblages for the Indian and Pacific Oceans. These assemblages indicate seasonality in cooling in the Atlantic basin, with greater cooling in northern summer than northern winter, not captured by the model simulations. Biases in the simulations of the tropical upwelling and thermocline found in the preindustrial control simulations remain for the LGM simulations and are partly responsible for the more homogeneous spatial and temporal LGM tropical cooling simulated by the models. The PMIP2 LGM simulations give estimates for the climate sensitivity parameter of 0.67° - 0.83°C per Wm⁻², which translates to equilibrium climate sensitivity for doubling of atmospheric CO2 of 2.6 - 3.1°C. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication An edited version of this paper was published by Springer. Copyright Springer-Verlag 2009. None eng geoscientificInformation